.bs {
    width: 70%;
    margin-top: 100px;
}
.bs th {background-color: #336699; color: white; padding: 0.8em;}
.bs tr {height: 35px;}
.bs td {border: 1px solid #336699; padding: 0.5em}
.centr {text-align: center}

.menu {margin-top:10px}
.menu_item {margin-right:30px}
.menu_item_right {float:right}

.auth-code {margin-top: 100px}
.book-img-thumbnail {height: 50px}